refactor(gepa): unify config extraction patterns

- Use isinstance(v, str) for predictor filtering (type-based)
- Use .get("tools", {}) for tools extraction (more Pythonic)

Both changes make the code more consistent and resilient to
config structure changes.

Author: Ju-usc

dspy/teleprompt/gepa/gepa_utils.py

@@ -217,8 +217,7 @@ def build_program(self, candidate: dict[str, str]):
                     if isinstance(instruction, str):
                         improved_predictors[pred_name] = instruction
 
-                if "tools" in config:
-                    improved_tools.update(config["tools"])
+                improved_tools.update(config.get("tools", {}))
 
         # Update predictor instructions
         for name, pred in new_prog.named_predictors():

dspy/teleprompt/gepa/instruction_proposal.py

@@ -385,9 +385,9 @@ def __call__(
             # Deserialize module config
             current_module_config = json.loads(candidate[module_key])
 
-            # Extract predictor keys (all keys except "tools")
+            # Extract predictor keys (strings are predictor instructions)
             # Predictor keys are expected to be 1 for tool modules and 2 for ReAct modules (extra extract predictor)
-            predictor_keys = [k for k in current_module_config if k != "tools"]
+            predictor_keys = [k for k, v in current_module_config.items() if isinstance(v, str)]
             logger.debug(f"Predictor keys: {predictor_keys}")
             primary_predictor_key = predictor_keys[0]
             extract_predictor_key = predictor_keys[1] if module_key.startswith(REACT_MODULE_PREFIX) else None